Electrically induced scattering textures in smectic A phases and their electrical reversal

Abstract

An electro-optic display mechanism is described which uses a smectic A liquid crystal of positive dielectric anisotropy. Information can be written on the display, stored there without a sustaining voltage i.e. has a memory, and subsequently can be erased electrically. The erase mechanism involves a dielectric re-orientation of the smectic molecules, and the writing mechanism involves a turbulent scattering state that resembles nematic dynamic scattering. The turbulent state is characterised by large rotating vortices whose plane of motion is orthogonal to the field direction. The conditions required to obtain scattering at the lowest practical threshold voltage are discussed.